An Xlet is very similar to a

Java applet Java applets were applet, small applications written in the Java (programming language), Java programming language, or another programming language that Compiled language, compiles to Java bytecode, and delivered to users in the form of Ja ...

and is originally introduced in

Sun Microsystems Sun Microsystems, Inc., often known as Sun for short, was an American technology company that existed from 1982 to 2010 which developed and sold computers, computer components, software, and information technology services. Sun contributed sig ...

Java TV Java TV is a Java (Sun), Java-based software framework designed for use on TV set-top boxes, based on components called Xlets. It is currently used only on the Connected Device Configuration, specifically for Interactive television, iTV applications ...

specification to support applications for

Digital TV Digital television (DTV) is the transmission of television signals using digital encoding, in contrast to the earlier analog television technology which used analog signals. At the time of its development it was considered an innovative adv ...

. Though Xlet looks superficially different from other application models in Java such as applet and MIDlet, it is actually meant to be a generalization of such models. The ''X'' in Xlet means an unknown, meaning that the Xlet framework may be used in any context rather than specific to Digital TV. Accordingly, Xlet was later re-introduced as a part of the Personal Basis Profile in the package, which is slightly different from the original design in the Java TV specification. The Xlet provision of a pause/resume feature is essential for a

set-top box A set-top box (STB), also known as a cable converter box, cable box, receiver, or simply box, and historically television decoder or a converter, is an information appliance device that generally contains a Tuner (radio)#Television, TV tuner inpu ...

(STB) environment, which has limited memory resources and restrictions on

bandwidth Bandwidth commonly refers to: * Bandwidth (signal processing) or ''analog bandwidth'', ''frequency bandwidth'', or ''radio bandwidth'', a measure of the width of a frequency range * Bandwidth (computing), the rate of data transfer, bit rate or thr ...

from the head-end provider. The current practice and intent of the Xlet framework is to provide downloadable applications for Personal Basis Profile (PBP) platforms. In particular, the

BD-J BD-J, or Blu-ray Disc Java, is a specification supporting Java ME (specifically the Personal Basis Profile of the Connected Device Configuration or CDC) Xlets for advanced content on Blu-ray Disc and the Packaged Media profile of Globally Execut ...

platform uses Xlets as its programming framework. While Sun has provided a

reference implementation In the software development process, a reference implementation (or, less frequently, sample implementation or model implementation) is a program that implements all requirements from a corresponding specification. The reference implementation ...

within which they provide a simple Xlet runner called RunXlet, at least one other open-source effort to implement an Xlet runner has been made.XleTView
- an open-source project to implement a Java-based Xlet runner, also supporting

Multimedia Home Platform Multimedia Home Platform (DVB-MHP) is an open middleware system standard designed by the DVB project for interactive digital television. The MHP enables the reception and execution of interactive, Java-based applications on a TV set. Interacti ...

(MHP) (not updated since 2004, based on JRE 1.1.8)

Code examples

The interface for an Xlet is defined in the javax.tv.xlet
/code> package: public interface Xlet thus an example of a stub Xlet is import javax.tv.xlet.XletStateChangeException; import javax.tv.xlet.XletContext; import javax.tv.xlet.Xlet; public class BasicXlet implements Xlet

Notes

{{Java (Sun) Interactive television Java device platform Articles with example Java code